Patents Assigned to Iwasaki Electric Co., Ltd.
  • Patent number: 4897576
    Abstract: In parallel connecting a starter to a luminous tube, the starter being formed by a coiled nonfusible metal wire which is wound to or laid along the outer wall of the luminous tube and a nonlinear capacitor which is in series connected to the nonfusible metal wire. As a result of this, the discharge lamp can be assuredly and stably lit with a small size ballast. Furthermore, pass of large current through the starter can be prevented even if the luminous tube is leaked. Furthermore, if the vacuum outer bulb is leaked or broken, the circuit of the starter can be opened by melting the nonfusible metal wire.
    Type: Grant
    Filed: August 18, 1988
    Date of Patent: January 30, 1990
    Assignee: Iwasaki Electric Co., Ltd.
    Inventors: Takenobu Iida, Jojiro Shiina, Minoru Yasukawa
  • Patent number: 4827190
    Abstract: A metal vapor discharge lamp has a luminous tube constituted by a translucent ceramic tube member, end caps hermetically fixed to both ends of the translucent ceramic tube member, and electrode supporting tubes hermetically inserted into respective end caps. One of the electrode supporting tubes serves also as an exhaust tube for evacuation and also as a reservoir for a metal charged in the luminous tube. The outer end extremity of this electrode supporting tube is hermetically sealed through fusion by application of heat. This hermetic seal is formed by fusing the end of the electrode supporting tube by application of heat thereto, while keeping a heat-shielding/absorbing plate held in close contact with the electrode supporting tube.
    Type: Grant
    Filed: December 2, 1985
    Date of Patent: May 2, 1989
    Assignee: Iwasaki Electric Co., Ltd.
    Inventors: Motonobu Masui, Yasuo Ban
  • Patent number: 4817447
    Abstract: A weather resistance tester comprising:(a) a U.V. radiation source,(b) a reflector,(c) a shield panel provided in the opening of the reflector and closing the opening for transmitting U.V. radiation therethrough and substantially blocking water vapor,(d) a sample support,(e) temperature adjusting device,(f) a compartment having accommodated therein the above elements (a)-(e),(g) a recycling duct provided with a heat exchanger and blower,(h) a humidifier and(i) a control device for giving operational instructions to maintain a sample on the sample support at a predetermined temperature while the lamp is on and to subject the sample to a condensation condition while the lamp is off.
    Type: Grant
    Filed: June 17, 1987
    Date of Patent: April 4, 1989
    Assignees: Dainippon Plastics Co., Ltd., Iwasaki Electric Co., Ltd
    Inventors: Yoshio Kashima, Hirofumi Kinugasa, Yasuo Yoshida, Teruo Iwanaga
  • Patent number: 4807085
    Abstract: A nonlinear capacitor for generating high-voltage pulses comprises a ferroelectric substrate, electrode layers formed on both sides of said substrate, a mineral glass coating covering the entire surface of the capacitor except for the connector portions for said electrode layers and for the outer peripheral surface of said ferroelectric ceramic substrate, and lead terminals electrically connected to the electrode layers through said connector portions.This construction prevents the mechanical oscillation due to electrostriction from being restrained, thereby permitting the capacitor to generate high-voltage pulses of great amplitude and energy.
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: February 21, 1989
    Assignee: Iwasaki Electric Co., Ltd.
    Inventors: Minoru Yasukawa, Takenobu Iida
  • Patent number: 4755721
    Abstract: This invention discloses a high pressure sodium vapor lamp having unsaturated vapor pressure type characteristics with sodium and mercury contained in an arc tube. The sodium is enclosed in an amount sufficient to exhibit unsaturated vapor pressure type characteristics while the mercury is enclosed in an amount M.sub.Hg calculated by the following formula: ##EQU1## where M.sub.Hg : the amount of mercury enclosed (mg)D: the internal diameter of the arc tube (cm)L: the electrode-to-electrode distance (cm)V.sub.olume : the volume of the arc tube (cc)V.sub.n : the rated lamp voltage (Volt).
    Type: Grant
    Filed: March 16, 1987
    Date of Patent: July 5, 1988
    Assignee: Iwasaki Electric Co., Ltd.
    Inventors: Toshiyuki Okada, Hiroyoshi Yokome, Akira Kosasa, Tomoyuki Habu, Yasuharu Yamamoto
  • Patent number: 4567403
    Abstract: In a high pressure discharge lamp device provided with an inductive stabilizer and a starting circuit consisting of a serial circuit of a resistor and a bimetal switch, a pulse waveform conversion circuit is arranged therein to reduce the pulse peak of the starting voltage and also broaden the pulse width of the starting voltage. The pulse waveform conversion circuit comprises a serial circuit of a resistor and a switching element, such as micro-gap element, which operates at a voltage lower than the starting voltage of the discharge lamp but higher than the secondary load-free voltage of the stabilizer.
    Type: Grant
    Filed: February 18, 1982
    Date of Patent: January 28, 1986
    Assignees: Iwasaki Electric Co., Ltd., Mitsubishi Mining & Cement Company, Ltd.
    Inventors: Yoshio Ohtagaki, Masafumi Ochi, Motonobu Masui, Kanichi Tachibana, Akio Uchida
  • Patent number: 4520294
    Abstract: There is disclosed a high pressure metal vapor discharge lamp which contains in an outer bulb a starting circuit connected in parallel with a light emitting tube having at least one pair of main electrodes. The starting circuit includes a ceramic capacitor surrounded by glass material and exhibiting a non-linear voltage-charge characteristic.
    Type: Grant
    Filed: August 11, 1983
    Date of Patent: May 28, 1985
    Assignee: Iwasaki Electric Co., Ltd.
    Inventors: Takenobu Iida, Shunichi Sasaki
  • Patent number: 4137483
    Abstract: A high pressure discharge lamp with a starting circuit contained therein includes an arc tube provided with a pair of opposed electrodes at the hermetically sealed opposite ends thereof. The interior of the arc tube is filled with at least a luminous metal and gas. The discharge lamp further includes a series circuit consisting of a thermo-responsive switch and a resistor and shunted to the electrodes of the arc tube, and an outer envelope for containing therein the series circuit and the arc tube. The resistance value of the resistor is set such that a sufficient current to induce a pulse of higher voltage than the starting voltage flows through the series circuit while, on the other hand, the current flowing through the series circuit is substantially equal to or less than the lamp current during the stable state of the lamp.
    Type: Grant
    Filed: December 2, 1976
    Date of Patent: January 30, 1979
    Assignee: Iwasaki Electric Co., Ltd.
    Inventors: Masafumi Ochi, Motonobu Masui, Ikuo Iwai